Powertrain
generic / SAE
P2AC1
Intake Air O2 Sensor Reference Voltage Circuit Low Bank 1
The reference voltage supplied to the intake air oxygen sensor on bank 1 reports a low condition. Lambda measurement on the intake side is unreliable.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / numberA / C1
Possible causes
- Reference wire shorted to ground high
- Internal short in sensor reference medium
- Connector pins corroded - high contact resistance low
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Inspection / repair
- Difficulty: medium
- DIY: shop recommended
- Estimated cost: 200–900 €
- Estimated time: 1–4 h
- Component: intake air o2 sensor b1
- Component: wiring harness
- Component: ecm
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012